/Engine/Source/Runtime/MovieSceneTracks/Public/Sections/MovieSceneSkeletalAnimationSection.h
bool GetRootMotionVelocity ( [FFrameTime](API\Runtime\Core\Misc\FFrameTime) PreviousTime, [FFrameTime](API\Runtime\Core\Misc\FFrameTime) CurrentTime, [FFrameRate](API\Runtime\Core\Misc\FFrameRate) FrameRate, FTransform & OutVelocity, float & OutWeight ) const